Apparatus for fluid treating roll film



April 29, 1947. P. R. T-ARR ET AL APPARATUS FOR FLUID TREATING ROLL FILM Filed May 16, 1944 v INVENTORS PHILIP 12.1'ARR 7 AND DELEERT C. CLINE ATTORNEYS Patented Apr. 29, 1947 APPARATUS FOR FLUID TREATING ROLL FILM Philip, R. Tarr and Delbert C. Cline, Silver Lake Village, Ohio Application May 16, 1944, Serial No. 535,882

3 Claims.

This invention relates to film tanks such as are used by photographers for the developing of exposed rolls of photographic film, and more especially it relates to tanks of the character mentioned having improved power operated means for effecting agitation of the fluid contents thereof, and improved technique of developer agitation.

In the developing of photographic film, the latter first is immersed in a developing solution for from five to thirty minutes, then immersed in a fixing solution for a few minutes, and subsequently is washed in water for a period of two hours or more, all of which operations usually are performed while the film is in a light-proof tank. The developing operations mentioned are best effected if the fluid in the tank is in agitation so that it moves over the film, and such agitation may be achieved manually or by poweroperated means, the latter being preferred because of the relatively long time required for obtaining optimum results.

When electrically operated stirring or agitation is employed there is always the possibility of water or other fluid from the tank reaching the electrical apparatus and incapacitating or clamaging the same, or creating a hazard to the operator. Accordingly one of the chief. objects of the invention is to provide a film tank employing motive power other than electricity for efiecting agitation of the contents thereoi.

Furthermore, in film tanks in which the filmreel is rotated continuously in one direction, the fluid eventually rotates with the reel and film so that there is substantially no movement of the film relatively of the fluid. In cases where the film is mounted spirally on the reel and does move relatively of the fluid the greatest relative movement occurs at the periphery of the film roll, with resulting lack of uniformity of development. Accordingly, two other important objects of the invention are to effect agitation of the contents of the film tank in a manner that causes the fluid thereof rapidly to flow relatively of the film in an improved manner; and to achieve uniformity of development of the film.

Other objects of the invention are to provide a film tank of the character mentioned that is composed of relatively few parts; that readily may be constructed substantially entirely of molded material such as plastic; that utilizes cheap and readily available motive power; that effects agitation of the contents of the tank by reciprocatory axial movement of the film reel; to provide a power operated film tank wherein the motor does not require lubrication; and, to provide a film tank with a fluid-operated motor built thereinto.

More specifically the invention aims to provide -905) 2 an improved reciprocating hydraulic motor especially adapted for use in film tanks, although it may be usefully employed in other situations. Other objects will be manifest as the description proceeds.

Of the accompanying drawing:

Fig. l is a diametric section a film tank embodying the invention, a portion thereof being shown in elevation;

Fig. 2 is a fragmentary portion of the structure shown in Fig. 1, on a larger scale, showing the piston and valve of the hydraulic motor in their respective alternative positions;

Fig. 3 is a section on the line of Fig. 1; and

Fig. 4 is a section on the line l l of Fig. 1.

Referring to Fig. l of the drawing, it will be se n that the film tank. of the invention comprises a sectional tank or container consisting of a base section ill in which is located the hydraulic motor, an intermediate section H superposed upon section it} and containing the film reel and developing fluid, and a top or cover section l2 upon said intermediate section, all of said sections being hollow and having substantially cylindrical peripheral walls. The base section ill a bottom wall l3, and the intermediate section H has a bottom wall ii, the arrangement being such as to provide a cham her [5 in the base section ill in the assembled condition of the container. The intermediate section H is secured upon the base section IE1 by a circumferential series of set screws i6, I5 mounted in suitable bosses formed on the respective sections, and a gasket ll preferably is interposed between the sections to prevent escape of fluid from the chamber it at the juncture of the sections. If desired the intermediate section it may be formed with a narrow flange [8 that telescopes into the base section ll for assur ing accurate registry of said sections.

The top or cover section E2 telescopes over the upper marginal portion of intermediate section H, and is formed with a circumferential tongue or tenon 20 that is received in a complemental groove in the upper margin of section it a means for positively excluding light from the interior of the latter. The cover section is formed with a tubular, axially disposed neck; 2! through which fluid is introduced to the interior of intermediate section H, said cover section also being formed with a pouring spout 22 adjacent thereto. Secured to the under side of the cover ii. in spaced relation thereto is a baiile plate 23 that obstructs the entrance of light through the filling neck. El and pouring spout 22, yet does not prevent the admission of fluid through said filling neck or removal of fluid by way of said pouring spout. The baffle 23 is secured to the cover l2 by a plurality of rivets or studs 24.

The intermediate section H with cover section i2 thereon define an internal developing chamber 26, in which chamber is located the film reel of the device. Said film reel is arranged on a vertical axis, and comprises a circular bottom section 2! that is integrally formed with a tubular axial hub 28, and a top section 29 mounted upon said hub, said sections preferably being formed of molded and hardened plastic material. The confronting faces of bottom section 21 and top section 29 are formed with respective spirally arranged grooves 38, 3| respectivel in which the marginal portions of a loosely coiled him 32 are receivable, the film being fed into the grooves manually by longitudinal movement starting at the outer end of the grooves, at the periphery of the reel sections. The top reel section 28 is supported by the hub 28, and is adjustable axially thereof so that the reel will receive films of difierent widths, as is usual in devices of this kind. Both reel sections are formed with a niultiplicity of perforations 33 therein to admit the passage of developing fluid therethrough, said perforations being located in the bottoms oi the grooves 3!, 3i. perforations 34 for the same purpose. The reel, as shown in Fig. l, is in its lowermost position, in which its bottom section 2! is resting upon the bottom wall M of tank section l, the periphe i s of both reel sections being spaced but sli from the adjacent circumferential surface of container section ii. In the operation of the tank the reel is reciprocated axially a short dis tance (about 13 inch) to effect agitation of the developing fluid (not shown) in the tank, said fluid being of ufiicient depth to cover as reel in all positions of reciprocation. The upper end of the tubular reel-hub 2-3 is closed by an integral cap 35 that is molded thereon, there being a metal insert 36 molded into said cap at the axis thereof and formed with an internally threaded bore that is open to the interior of the hub.

The film reel is reciprocated by means of a vertical axial rod 38 that is disposed within the hub 28 and has its upper end threaded into meta-l inseii: 35 in the cap of the hub. The rod 38 is the piston rod of a fluid pressure operated motor located in. the chamber 5 at the bottom of the tank. The rod 33 extends through the bottom wall M of the intermediate section If and said bottom wall is formed with an upw ly extending, tubular, axial boss or bearing 39 in which the rod 353 i slidingly received. The boss is exterior-1y tapered toward its upper end, and extends into the reel hub 23 for substantially two-thirds the distance to the top th eof. A bellows-like or corrugated sleeve 4% of rev lient rubber composition embraces the upper end portion of the boss 39 and the adjacent upper end portion of the rod Said sleeve prevents the passage of fluid from either chamber l5 or 23 to the other, yet permits unrestricted reciprocation of the rod 38. The boss 33 serves a guide for the film reel, and also serves as a loose bearfor the rod 38.

The piston rod 33 is connected at its lower to the piston 42 of a fluid pressure motor, the cylinder of which consists of a circular wall 43 formed integral with bhG bottom 2.; of the tank. section i2, said wall 43 being located within the .iamber l5 concentric with the axis thereof. The piston 42 has a peripheral gasket or packing 4 3 of soft rubber or the like that has sliding and sealing engagement with the inner circumferential surface of the cylinder wall 43. The piston The hub 28 also is formed with 42 preferably is of hard molded material, and is formed with a circular axial recess 45 in the bottom face thereof. Molded into the piston 42 is a metal valve housing 46 that is located at the axis of the piston, and is of inverted cup-shape, the open side of the insert being downwardly presented and open to the piston recess 45. The piston rod 38 is attached to the piston by being threaded into the metal valve housing 46, and a helical compression spring 4'! is positioned about the piston rod, between the wall It and the valve housing 46, with the result that the tank reel and the motor piston are urged downwardly toward their lowermost positions. The lowermost position of the piston 42 is somewhat above the bottom wall I 3 of the tank, as is clearly shown in the drawin The valve housing 46 is formed in its circumferential wall, near the top thereof, with a plurality (six) of radial apertures 50, 50, and formed in the piston 42, in continuation of said apertures, are respective angular ducts 5| that terminate on the top face of the piston, said ducts constituting discharge ports from the valve 'mechanism. Slidably mounted for vertical recipr cation in the valve housing 45 is a valve 52 that consist of a relatively wide ring-shaped peripheral portion and an internal transverse web 53 located intermediate the ends thereof, said web being formed with a plurality of apertures 54, 54 for the passage of fluid therethrcugh. The area of the apertures 54 is at least as great as the area of the apertures 59 in the valve housing. The arrangement is such that when the valve 52 is moved to its upper position it will close the apertures 5!), as shown in l and in broken lines in Fig, 2, and when moved to its lower position will uncover the apertures 55), as shown in full lines in Fig. 2.

For moving the valve 52 axially between valveopening and valve-closing positions a metal leaf spring 55 is employed. The spring 56 is somewhat narrower than the diameter of the valve 52, and extends diametrically across the recess 45 in the bottom of the piston 42, the end portions of the spring being received in respective slots 5"! in the peripheral wall of the recess 45, on diametrically opposite side thereof. The spring 55 is somewhat longer than the distance between the slots 51 with the result that the spring normally is bowed, either upwardly or downwardly, as shown in Figs. 1 and 2 respectively, and may be caused to move from one of said bowed positions to the other. Such movement of the spring 56 is utilized for moving the valve 52 alternately to its upper and lower positions and to this end an axial stem 5'! is secured to the web 53 of said valve and extends downwardly therefrom, said stem extending freely through an aperture 58, Fig. 2, in said spring 56. The stem 57 has flanges or collars 59, 59 thereon that are in spaced re lation axially of the stem, one of said being disposed above the spring, and the other below the spring. Th arrangement is such. as to provide lost motion enabling the spring 6 to move a substantial distance without moving the valve 52, the latter being moved only as the spring snaps over center in the final phase of its mov ment to its alternative position.

For moving the spring 56 between its upwardly bowed position shown in Fig. l and its downwardly bowed position shown in 2, an operating rod 62 is provided, which rod is secured to the spring adjacent one end thereof. A portion of the rod 62 extends below the spring 55 and below the piston 42, the arrangement being such that when the piston is moving downwardly, with spring 52 in downwardly bowed position as shown in Fig. 2, the rod 62 will strike the bottom wall 13 of base section Ill while the piston is still spaced considerably above said bottom wall. Then movement of the piston relatively of the rod will cause the spring 56 to move to its reverse or upwardly bowed position, as is clearly shown in Fig. 1, thus reversing the position of the valve 52. For reversing the position of the spring 56 and valve 52, that is, for moving them from the position shown in Fig. 1 to the position shown in Fig. 2, the operating rod 62 is extended upwardly through an aperture 63 in the piston 42, the upper end of the rod being located some distance above the piston and its cylinder wall 43. The arrangement is such that the p t n 42 d rod 62 may move upwardly a determinate distance before the upper end of the rod strikes the bottom wall 14 of intermediate tank section I l; thereafter relative movement of the piston and rod will cause the spring 56 to move to its reverse or downwardly bowed position, as shown in Fig. 2, thus reversing the position of valve 52. The reversing of the valve 52 results in the reversing of the movement of the piston 42, as presently will be explained. Thus the length of the operating rod 62 determines the extent of reciprocation of the reel in the tank. Preferably when the piston is in its uppermost position its top face is flush with the top of cylinder wall 43. The operating rod 62, in reversing the position of the spring 56, first flexes or deforms the spring in the region of its point of attachment thereto. After such deformation has reached sufficient magnitude the spring quickly snaps over center. The lost motion connection between the spring and the stem 51 of valve 52 is such that the valve is operated by the final snap movement of the spring, thus assuring rapidity of operation that is practically instantaneous.

The fluid for operating the piston 42 of the fluid pressure cylinder preferably is water, the same being admitted to the cylinder at the bottom thereof. To this end the bottom wall l3 of the tank section has a radial duct or tunnel 65 formed therein and extending from said cylinder to an inlet neck 66 on the exterior of said section. A flexible pipe 61 extending to a supply of water under pressure (not shown) may be connected to the neck 66 in any suitable manner, as by the clamp 68. The chamber I5 is formed with an outlet port 69 extending through a neck 10 on the exterior of tank section In, and a suitable drain pipe 1| may be secured to neck 19, as by means of clamp 12.

In the operation of the improved tank, the film 32 is mounted in the reel and the chamber 26 of the tank is filled with developing fluid sufiicient to cover the film in all positions of reciprocation, that is, about inch above the top of the film as shown in Fig. 1. Then with the cover I2 in place to prevent the entrance of light to the tank, water is admitted through the pipe 61 to effect operation of the hydraulic motor. At the beginning of operations the piston 42 is in the lower position shown in Fig. 1 and the valve 52 is in its upper position so as to close the apertures or ports 50. Thus the water entering beneath the piston 42 builds up pressure to lift the piston against the force of the spring 41, and thereby to lift the film reel mounted upon the upper end of piston rod 38. After the piston moves upwardly a determinate distance, the op- 6 erating rod 62 engages the wall 14, and continued rise of the piston relatively of said rod causes the spring 56 to move over center and snap to its downwardly bowed position, as shown in Fig. 2. This movement of spring 56 quickly lowers the valve 52 and thus uncovers the ports 56 in the valve housing 46, with the result that the water under pressure below the piston and valve is enabled to pass through said ports and the ducts 5i and to flow over the cylinder wall 43, and flow from the tank by way of the drain pipe H. Opening of the ports '56 relieves the pressure behind the piston 62, whereupon the spring 41 forces the piston downwardly, thus lowering the film reel. As the piston approaches the bottom of its cylinder, the operating rod 62 strikes the bottom wall l3 of the tank whereby the spring 56 is snapped over center to its alternative position and the valve 52 lifted to close the ports '59, as shown in Fig. 1. This completes a cycle of operation which is repeated continuously and automatically as long as water under pressure is admitted through the pipe 61.

The invention provides an improved tank for the development of photographic film wherein all the film is developed to a uniform degree. The motive power of the tank is self-contained, and the hazards incidental to the use of electric motive power are obviated.

Modification may be resorted to without departing from the spirit of the invention, or the scope thereof as defined by the appended claims.

What is claimed is:

1. In a film tank of the character described, the combination of a housing formed interiorly with a developing chamber formed with a centrally disposed upwardly extending apertured boss, a film reel in said chamber comprising top and bottom sections connected to a hollow axial hub, said reel adapted to support a film by engagement with the margins thereof, the bottom section of the reel, at least, being formed with a multiplicity of perforations therethrough, the hub of said reel telescoping over said boss and having a closed upper end, and a power operated rod extending upwardly through said boss and connected at its upper end to the closed end of the reel-hub, said rod adapted to effect axial reciprocation of said film reel.

2. A combination as defined in claim 1 including a sleeve of resilient material embracing the upper end portion of the boss and the adjacent portion of the rod to prevent the passage of developing fluid into the aperture in the boss.

3. A combination as defined in claim 1 including perforations formed in the reel hub to enable the passage of developing fluid therethrough.

PHILIP R. TARR. DELBER'I' C. CLINE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,916,207 DeFrancisco et a1. July 4, 1933 2,112,605 Pless Mar. 29, 1938 2,345,682 Neuwirth Apr. 4, 1944 1,910,644 Smith May 23, 1933 2,321,423 Rogers June 8, 1943 2,319,608 Kraut May 18, 1943 2,073,306 Hughey Mar. 9, 1937 1,645,452 Riggle Oct. 11, 1927 2,128,921 ,Draeger Sept. 6, 193a 

